> WASM seems to provide a pretty good basis for building many things low level things on, but less useful for higher level languages which might want garbage collection

Would it be possible to implement a garbage collector in WASM? And could it be a concurrent garbage collector, using advanced techniques such as memory barriers?

It would be cool if we could run e.g. Haskell or Go in WASM. Or even C programs which rely on the Boehm collector.